A modified gonadotropin-releasing hormone (GnRH) antagonist protocol failed to increase clinical pregnancy rates in comparison with the long GnRH protocol.

The purpose of this prospective randomized study was to compare stimulation characteristics and IVF outcomes of the standard long GnRH agonist protocol for ovarian stimulation with a modified GnRH antagonist protocol. Starting GnRH antagonist in a flexible protocol according to the size of the leading follicle, with simultaneous augmentation of 75 IU recombinant FSH, failed to increase clinical pregnancy rates.